Objective
Given the increasing number of older people, China has become an aging society. A mobile health service is a type of health informatics that provides personalized healthcare advice to those who require it, especially the older people and the middle-aged. However, few studies consider the adoption of mobile health services with regard to older and middle-aged users. This paper explored a research model based on the value attitude behavior model, theory of planned behavior, and four aging characteristic constructs to investigate how older and middle-aged citizens adopted mobile health services.

Method
The hypothesized model was empirically tested using data collected from a survey of 424 residents older than 40 years in China. Structural equation modeling was used to estimate the significance of the path coefficients.

Results
The findings revealed that (1) perceived value, attitude, perceived behavior control, and resistance to change can be used to predict intention to use mobile health services for the middle-aged group; (2) perceived value, attitude, perceived behavior control, technology anxiety, and self-actualization need positively affected the behavior intention of older users; and (3) subjective norm and perceived physical condition showed no significant effects on the behavior intention to use mobile health services for the two groups. The theoretical and practical implications and contributions of this study are then discussed.